During the manufacturing of a MEMS surface movable structure, a sacrificial layer with a large thickness is often manufactured. When etching the sacrificial layer, it always requires that the etching morphology has a certain angle, before a movable layer (such as a polysilicon layer) is deposited. In the prior art, when performing a photolithography process on the slope, as the slope is relatively high (usually the height is greater than 2 μm), after spin-on PR coating, the thickness of the photoresist on the top of the slope and on the bottom of the slope will not be uniform, the photolithography energy for the bottom of the slope during the photolithography process is high, which will lead to an overexposure of patterns on the top of the slope.
Therefore, it is necessary to address the above problem and provide a photolithography method and system based on the high step slope.